fix(logger): middleware stores initial persistent attributes correctly

[dreamorosi]

Description of your changes

In #1328 it was reported that the Logger middleware injectLambdaContext was not clearing correctly the state and potentially leaking attributes set during an execution in the subsequent one.

Prior to this PR the middleware was improperly storing the initial persistent attributes of each logger instance passed to the middleware. This caused issues when clearing the state after each invocation, since the initial persistent attributes were now unusable.

This PR fixes the issue and adds new unit tests. Once merged this PR will close #1328.

Once merged, this PR closes #1328.

How to verify this change

See checks under the PR as well as integration test run here. New unit tests were added to demonstrate the fix & avoid future regressions.

Related issues, RFCs

Issue number: #1328

PR status

Is this ready for review?: YES
Is it a breaking change?: NO

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding changes to the examples
• My changes generate no new warnings
• The code coverage hasn't decreased
• I have added tests that prove my change is effective and works
• New and existing unit tests pass locally and in Github Actions
• Any dependent changes have been merged and published
• The PR title follows the conventional commit semantics

Breaking change checklist

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

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[am29d]

🚢